"It turns out - and I did not know this - most soil is at ground level," Colbert testified Friday. Also, "It was hotter than I like to be."

Yet Colbert expressed befuddlement that more Americans aren't clamoring to "begin an exciting career" in the fields and instead are leaving the work to illegal immigrants.

Colbert stayed in character as a pompous Comedy Central news commentator as he offered a House hearing his "vast" knowledge, drawn from spending a single day on a New York farm as a guest of the United Farm Workers.

Colbert pleaded with the lawmakers to do something about illegal workers, because "I am not going back out there."

After a day of farm work, he said, "I don't even want to watch Green Acres again."

After praising Colbert for drawing an unusually large audience to the immigration subcommittee hearing, House Judiciary Chairman John Conyers asked him to leave the room - and to leave the job of testifying to the expert witnesses on the panel, including Farm Workers President Arturo Rodriguez.

"You run your show, we run the committee," said Conyers, D-Mich.

Colbert responded that he was there at the invitation of subcommittee chairwoman Zoe Lofgren, D-Calif. Conyers later withdrew his request, and Colbert launched into his schtick, insisting he wanted his tomatoes picked by Americans, not Mexicans.

"I'm not a fan of the government doing anything," Colbert insisted. "But I've got to ask, Why isn't the government doing anything?"